1. Field of the Invention
The present invention relates to an endoscope insertion shape analysis system and a biological observation system, and more particularly, to an endoscope insertion shape analysis system and a biological observation system capable of acquiring information for assisting insertion operation of an insertion portion of an endoscope.
2. Description of the Related Art
Endoscopes are conventionally widely used in medical and industrial fields or the like. Furthermore, endoscopes in the medical field are used when performing observations and various treatments of living tissue or the like.
Especially when an insertion portion of an endoscope is inserted from the anus of an examinee to perform observations and various treatments of the lower digestive tract, an endoscope insertion shape analysis system capable of detecting the position of the insertion portion in the body cavity and bending condition or the like is used together with the endoscope in order to smoothly insert the insertion portion into the crooked body cavity.
An endoscope insertion shape analyzer is described, for example, in Japanese Patent Application Laid-Open Publication No. 2004-358095 as an apparatus having a function substantially the same as that of the aforementioned endoscope insertion shape detection system.
Japanese Patent Application Laid-Open Publication No. 2004-358095 discloses a configuration in which a portion corresponding to a loop forming candidate of an insertion portion of an endoscope is divided into n portions, three-dimensional coordinate values of each dividing point projected onto a predetermined plane (z=0 plane) are transformed into feature values as P-type Fourier descriptors and the feature values are compared with instructor data to thereby judge whether or not the portion corresponding to the loop forming candidate forms a loop shape.
Furthermore, the endoscope insertion shape analyzer of Japanese Patent Application Laid-Open Publication No. 2004-358095 has a function of judging that the large intestine has stretched when it is detected that a moving distance of a distal end portion of the endoscope inserted in the large intestine within a predetermined period of time is equal to or less than a predetermined threshold and the length of the insertion portion of the endoscope inserted in the large intestine continues to increase.
Furthermore, the endoscope insertion shape analyzer of Japanese Patent Application Laid-Open Publication No. 2004-358095 is configured by including shape analysis means for analyzing the shape of the insertion portion of the endoscope and information providing means for providing information on the shape of the insertion portion according to the analysis result of the shape analysis means. In such a configuration, the endoscope insertion shape analyzer of Japanese Patent Application Laid-Open Publication No. 2004-358095 can provide information that leads to improvement of insertability of the endoscope.